1. Field of the Invention
This invention relates to hybridoma cell lines and monoclonal antibodies produced therefrom which may be used to detect ceftiofur.
2. Description of the Prior Art
Ceftiofur is a broad-spectrum, .beta.-lactamase-resistant cephalosporin which exhibits excellent antimicrobial activity by virtue of its 2-(2-aminothiazol-4-yl)-2-methoxyaminoacetamide substituent at the C-7 position of the cephem nucleus (Labeeuw and Sahli, U.S. Pat. No. 4,464,367; Yancey et al., 1987, Am. J. Vet. Res., 48:1050-1053). Ceftiofur has been approved by the FDA and is used for the treatment of respiratory diseases in cattle and horses (Food and Drug Administration, 1988, Fed. Regist., 53:5369-5370; and 1991, Fed. Regist., 56:119).
Current detection methods for cephalosporins include HPLC procedures (Rouan, 1985, J. Chromatogr. 340:361-400) and biological assays (Wise et al., 1980, Antimicrob. Agents Chemother., 17:84-86). Recent HPLC methods for ceftiofur can detect 0.5 ppm ceftiofur equivalents (Jaglan et al., 1990, J. Assoc. Off. Anal. Chem., 73:26-30; Gilbertson et al., 1990, J. Agric. Food Chem., 38:890-894). Other methods for the detection of ceftiofur which have been described include agar gel diffusion (Cervantes et al., 1993, Am. J. Vet. Res., 53:573-575. Owens et al., 1990, J. Dairy Sci., 73:3449-3456), "DELVOTEST-P", which is a calorimetric bacterial inhibition test (Jaglan et al., 1992, J. Dairy Sci., 75:1870-1876. Owens et al., 1990, ibid), the Bacillus stearothermophilus disk assay, the Charm test II, which is a receptor-binding assay (Jaglan et al., 1992, ibid), and a cylinder-plate microbiological assay (Jaglan et al., 1992, ibid; Gilbertson et al., 1990, ibid). Unfortunately, these tests require labour-intensive sample preparations, lengthy data acquisition times, and in some cases costly and sophisticated equipment.
A commercial immunoassay for ceftiofur is currently available (Idetek Inc., Sunnyvale, Calif.). However, the assay is based upon a polyclonal antibody for ceftiofur rather than a monoclonal antibody.